This invention is concerned with a device for printing indicia on substrates having associated therewith a disposable ink cartridge and means for filling said cartridge.
Flexographic code dating machines are constant motion marking devices which continuously print certain indicia in ink on a substrate such as a web used ultimately in the packaging of goods. Such machines generally include a frame assembly having a mounting shaft which allows the machine to be mounted to a web feeding machine. The frame assembly has rotatably mounted thereon a free spinning print wheel or cylinder which on its periphery carries the indicia to be printed. The web, traveling below the frame, engages the print wheel and rotates it to effect the printing. Adjacent the print wheel on the frame assembly is a transfer roller which contacts the print wheel. Adjacent the transfer roller is a fountain roller which is also in contact with the transfer roller. The fountain roller contacts a supply of ink from an ink source and transfers ink adhering to its surface to the transfer roller which in turn deposits ink on the indicia of the print wheel. The print wheel then imprints the indicia on the moving web.
In the past, the ink source for use with constant motion marking devices consisted of a housing or reservoir containing a supply of ink in which the fountain roller was immersed. These reservoirs had to be refilled with an ink supply after it was expanded. Other containers protruded through the housing and were equipped with an ink absorbent sponge material which contacted the fountain roller. These prior ink sources have several drawbacks. Refilling a used cartridge with ink is a tedious and messy operation often causing the user to contaminate his hands and clothes with ink. The refilling operation is also time consuming. If replacement ink cartridges are used filled with ink and stored for later use it was found that the solvent carrier for the ink would evaporate from the cartridge due to inadequate sealing. Nothwithstanding the obvious advantages of these disposable cartridges, they have a limited lifetime, e.g. about 4 hours.
The present invention, on the other hand, provides a constant motion printing device having associated therewith a disposable ink cartridge and a means for introducing a supply of ink to the cartridge to extend its life. The preferable cartridge contains an ink absorbent pad and a sealing means which allows storage of the ink filled cartridge indefinitely without danger of evaporation. This cartridge allows the user to operate the printer with very litte interruption to regenerate the ink supply, to change ink supplies quickly and without spillage and to store cartridges without concern for ink evaporation. The means for introducing a supply of ink allows the user to extend the useful life of the cartridge during operation of the device from 4 hours to about 70 hours.